UASP appears broken on this controller or it's drivers? Multiple Linux kernels have been coded to ignore UASP-declaring firmware support on this controller chip or blacklisted it altogether.
There at least three other USB to SATA bridge or controller chips that work very well and can be had for peanuts.
Thanks, I did see those linux problem reports. And I also have another adapter that works OK. But here is why I'm still looking: I used this thing occasionally for over two years, and it did work well in UASP. ( I am using win 10.)
I messed the adapter up recently, and here's how: I got a newer USB card (asmedia chipset). If I connect this adapter, it crashes something in the card's drivers or windows and disk not recognized. I'm using the standard drivers which windows installed for this card, but I tried a couple of others.
Oddly, it still worked fine on my older USB card (via chipset), which I kept installed as well as the new one. So, I re-flashed the adapter itself, thinking it might cure the incompatibility. In fact I tried most of the firmware at usbdev.ru, and station-drivers. The latter only had bin files for NS1068 chips, but they still worked. None had UASP.